A hallmark of KSHV infection is that the virus persists, and causes disease, by disabling aspects of its host's anti-viral innate and adaptive immune responses. Understanding how the virus manipulates its host in this way will be vital to developing effective therapies against this human pathogen. Studies of KSHV infection in an in vivo model are therefore an essential aspect of the research to be addressed by this Program Project. The role of the Genetic Core will be to oversee the development and customization of a humanized NSG mouse model of KSHV infection, which will enable in vivo studies of KSHV infection, persistence and pathogenicity. The Core will initially evaluate different KSHV infection routes, to identify the optimal way to obtain persistent infection, and will establish appropriate assays to monitor KSHV infection levels (lytic and latent gene expression), and to analyze the effect of infections on human cells and hematopoiesis. The Core will provide the technical expertise and training to infect and analyze humanized mice, thereby facilitating studies of the different KSHV mutants that will be generated by each of the Projects and The Virology Core. Finally, the Core will provide the capability to engineer the human cell components of humanized mice prior to engraftment, using lentiviral vectors expressing shRNAs or mRNA nucleofection of TALENs, in order to address questions about the role of human proteins, miRNAs and specific pathways in KSHV infection.